sx4fandomcom-20200213-history
E-Throttle
One of the most critized "features" of the SX4 is the electronically controlled throttle, which seems to lag behind the pedal (at best) and makes it difficult to shift smoothly (at worst). Why, you might ask, did Suzuki bother with the expense and complexity of an electronic throttle on a mid-range compact like the SX4? The same reason that many automakers are spending money on diminishing returns these days: emissions control. Yes, much like the intake the e-throttle is a system of compromise, designed primarily NOT for performance (which I assume is the goal of anyone reading this article) but for a mix of economy and emissions. The problem that many SX4 owners have with the E-Throttle is the lack of response (or speed of response) compared to perceived pedal input. This problem could be dealt with in one of several ways; first, you could add resistance to the pedal so that it moves more slowly - and thus the opening of the e-throttle would seem more "in line" with the position of the pedal. Unfortunately, that does not actually increase response, it only decreases the awareness that the e-throttle and pedal are not synchronized (some e-throttle pedals are already designed like this) and thus does not actually change response although the interpretation of movement by the user would be improved. Secondly, the ECU could be made to open the E-Throttle at a faster rate which would be the "Holy Grail" of throttle tuning - but of course the ECU is locked down pretty tight and nobody has had much luck modifying it directly, making this solution pretty far-off unless someone cracks the ECU codes. That leaves one more option - tricking the pedal itself into opening faster. This is not the IDEAL method, as the e-throttle won't open at a faster rate, it will only open MORE for a given level of pedal effort, roughly the effect gained by stomping the pedal to the floor as hard and fast as possible. Again, the e-throttle will still take the same amount of time to go from closed to fully open, but it won't take as much pedal effort - although this method does have the effect of reducing sensitivity, not increasing it, by making the pedal operate over a narrower range. There is a product on the market which does modify the signal from the pedal to the ECU. It is sold under the brand "Sprint Booster" for the SX4 as well as other e-throttle vehicles. The Sprint Booster is installed in-line between the pedal and the ECU and modifies the signal from the pedal, leaving it the same value as stock when the throttle is closed, and then drastically increasing the voltage compared to stock the moment the pedal is moved. While this method does send a signal to the e-throttle to open more aggressively for the same amount of pedal travel, it cannot actually increase the SPEED at which the e-throttle opens - it only gives the effect of 'flooring it' without the fun of actually 'flooring it.' Because the Sprint Booster can only work within the range of the stock pedal the overall result is a LOSS of sensitivity as the last part of the range (wide open throttle) is reached much sooner than stock giving the effect of "dead travel" at the end of the pedals range, in other words - you have simply shifted the output of the pedal UP but at the same time made it more NARROW, none of which actually makes the e-throttle open any faster than it would have without the $350+ Sprint Booster installed. One of the projects on my back burner is a much, much cheaper device which leaves the pedal signal alone when the throttle is closed but ramps the voltage up in a linear, user adjustable manner. (so I can live out my dream of having an SX4 with only two throttle positions: closed and wide open throttle - like a bumper car ^_^ )